Thursday, November 19, 2015

Caltrans' New Landslide Tracker

Last Chance Grade on US 101 in Del Norte County.
Southern California is no stranger to slides, as last month’s mudslide that closed the Grapevine demonstrates. That was a relatively unusual occurrence. Not so for a four-mile segment of US 101 known as Last Chance Grade. Located in Del Norte County, 10 miles south of Crescent City, Last Chance Grade is an area of highway prone to geological activity. A 2000 geological study conducted by the California Geological Survey mapped over 200 active slides within the corridor area.

The slide activity is a serious concern because there’s no viable alternative route in the event of a complete failure of the roadway due to a landslide. Without a detour, residents could be cut off from medical care, schools and other important services, and the economic impacts would be devastating

A new highway alignment will be constructed eventually that will offer a permanent solution to instability and potential roadway failure. In the meantime, the department has begun using a new, advanced, and multi-faceted system to monitor landslide activity at Last Chance Grade. Check out the video below to see how this sophisticated system works.